Claims
- 1. In a downhole tool disconnect system for a well having a tubing string extending downhole and a tool connected to the tubing string, the tool having a disconnect joint between an upper tool portion connected to a lower end of the tubing string and a lower tool portion releasably connected to said upper tool portion; an improved release mechanism for said release joint comprising:
- releasable locking means for releasably connecting said lower tool portion to said upper tool portion adjacent said disconnect joint;
- fluid operated release means operatively connected to said releasable locking means for unlocking of said locking means upon activation of said fluid operated release means and subsequent actuation of said release means; and
- electrical means operatively connected to said fluid operated release means to provide an electrical signal to said fluid operated release means to activate said fluid operated release means and permit actuation thereof upon a predetermined fluid pressure differential between an internal fluid in the tubing string and external fluid in the well.
- 2. In a downhole tool disconnect system as set forth in claim 1 wherein:
- said fluid operated means includes a piston operable at a predetermined fluid pressure differential between external fluid in an annulus outside said tool and internal fluid within said tool.
- 3. In a downhole tool disconnect system as set forth in claim 1 wherein:
- a hydraulic fluid reservoir is provided in said tool for pressurized hydraulic fluid for actuation of said fluid operated release means; said hydraulic fluid in said reservoir being pressurized by annulus fluid flowing down said tubing string and said tool.
- 4. In a downhole tool disconnect system as set forth in claim 3 wherein:
- a piston is operatively connected to said hydraulic fluid reservoir for pressurizing hydraulic fluid therein, said piston being exposed on one side thereof to annulus fluid and exposed on an opposed side to hydraulic fluid.
- 5. In a downhole tool disconnect system as set forth in claim 1 wherein:
- a cylinder is mounted within said tool receiving said piston for reciprocal movement; and
- a rod is mounted centrally of said cylinder; said piston being mounted on said rod within said cylinder for reciprocal movement.
- 6. In a downhole disconnect system as set forth in claim 5 wherein:
- a stop member for said piston is mounted on said rod; and shear pins releasably secure said stop member to said rod, said shear pins being sheared upon said piston contacting said stop member under a predetermined force from said drilling fluid for movement of said piston to a position to permit drilling fluid to bypass said piston for pressurizing said hydraulic reservoir to permit actuation of said disconnect upon a drop of pressure in said hydraulic fluid reservoir below a predetermined minimum amount.
- 7. In a downhole disconnect system as set forth in claim 1 wherein:
- said electrical means comprises a solenoid operated valve operable when energized to permit a flow of pressurized hydraulic fluid to said fluid operated release means, said solenoid operated valve when deenergized preventing flow of pressurized hydraulic fluid to said fluid operated release means.
- 8. In a downhole disconnect system as set forth in claim 7 wherein:
- a hydraulic fluid reservoir is provided in said tool; and pressurizing means responsive to annulus fluid pressurizes hydraulic fluid within said hydraulic fluid reservoir.
- 9. In a downhole tool release system as set forth in claim 1 wherein:
- said tubing string comprises coiled tubing and said electrical means comprises a wireline cable which extends through said coiled tubing to provide an electrical signal for activating said release means.
- 10. In a downhole tool release system as set forth in claim 9 wherein:
- a clamp within said tool is secured to said electrical cable adjacent the lower end of said coiled tubing for anchoring said wireline cable thereat; and
- cable release means responsive to tension forces exerted by said electrical cable connected to said clamp to release said clamp and wireline cable for retrieval from said coiled tubing.
- 11. In a downhole tool release system as set forth in claim 1 wherein:
- said locking means comprises a plurality of latches between said tool portions movable between locked and unlocked positions.
- 12. A fluid operated release means for a downhole tool having a disconnect joint between an upper tool portion connected to a tubing string and a lower tool portion releasably connected to the upper tool portion; said fluid operated release means comprising:
- a hydraulic fluid reservoir in said tool;
- means responsive to pressurized drilling fluid in said tool to pressurize hydraulic fluid in said hydraulic fluid reservoir;
- releasable locking means for releasably connecting said lower tool portion to said upper tool portion;
- a piston operatively connected to said locking means to effect unlocking thereof upon actuation of said piston;
- fluid passage means between said hydraulic fluid reservoir and said piston; and
- valve means in said fluid passage means to permit in one position the flow of pressurized hydraulic fluid from said reservoir to said piston for actuation of said piston and unlocking of said locking means to disconnect said upper portions from said lower tool portion.
- 13. A fluid operated release means as set forth in claim 12 wherein:
- said hydraulic fluid reservoir include a cylinder, a piston mounted within said cylinder for pressurizing hydraulic fluid therein; and
- means permitting the flow of pressurized drilling fluid within said cylinder for forcing said piston against the hydraulic fluid for pressurizing the hydraulic fluid.
- 14. A fluid operated release means as set forth in claim 13 wherein:
- a rod is fixedly mounted within said cylinder and said piston is mounted on said rod for relative reciprocal movement.
- 15. A fluid operated release means as set forth in claim 14 wherein said piston has an annular seal thereon for sealing against the inner surface of said cylinder and said cylinder has an inner annular groove therein to receive said annular seal therein in a fully retracted position of said piston when the pressurized hydraulic fluid is below a predetermined fluid pressure,
- said pressurized drilling fluid bypassing said piston in the fully retracted position of said piston to permit the flow of annulus fluid into said hydraulic fluid reservoir.
- 16. A fluid operated release means for a downhole tool having a disconnect joint between an upper tool portion connected to a coiled tubing string and a lower tool portion releasable connected to the upper tool portion, the tool having an outer housing and a wireline cable extending centrally of said outer housing to define an annulus therebetween, said fluid operated release means comprising:
- a source of hydraulic fluid;
- means responsive to pressurized annulus fluid in said tool to pressurize said hydraulic fluid;
- releasable locking means for releasably connecting said lower tool portion to said upper tool portion including a plurality of latches engaging said outer housing in a latched position and a slidable sleeve in the annulus maintaining said latches in latched position;
- a plurality of shear members releasably holding said slidable sleeve in an upper position for maintaining said latches in locked position; and
- a piston mounted above said slidable sleeve and effective upon actuation thereof from pressurized hydraulic fluid to force said sleeve downwardly for shearing said members and releasing said latches for disconnect of said upper tool portion from said lower tool position.
- 17. A fluid operated release means as set forth in claim 16;
- said piston and said slidable sleeve are spaced vertically from each other in the latched position of said latches to permit annular fluid flow between said piston and said sleeve, said piston when actuated by pressurized hydraulic fluid moving downwardly into contact with said slidable sleeve to block annular fluid flow and effect a pressure buildup above said sleeve acting against said sleeve, said piston and said sleeve being forced downwardly by respective pressurized hydraulic fluid and pressurized annulus fluid for shearing said members to release said latches for disconnect of said upper tool portion.
- 18. A fluid operated release means as set forth in claim 17 wherein;
- a surface detectable fluid pressure change is provided upon contact of said piston against said slidable sleeve.
CROSS-REFERENCE TO RELATED PROVISIONAL APPLICATION
This application claims the benefit of U.S. Provisional Application Ser. No. 60/015,252 filed Apr. 23, 1996 and entitled Coiled Tubing Drilling Head.
US Referenced Citations (19)